Antenna



FIG. 1 is a front plan view of an antenna with a base in broken lines;

FIG. 2 is a side elevation view thereof;

FIG. 3 is a side elevation view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a rear plan view thereof; and,

FIG. 7 is a top perspective view thereof.

The broken lines represent environment only and form no part of the claimed design. 

CLAIM The ornamental design for an antenna, as shown and described. 